The present invention relates to an instrument for resectioning hemorrhoids for the minimal invasive subanodermal removal of hemorrhoidal tissue.
Hemorrhoidal ailments account for the most frequent rectal disease found in the Western civilized world; the disease frequency is said to be 50% among the population over 50 years. Hemorrhoids are vessel convolutes covered with mucous membrane, which are noticed by bleeding, pressure sensation or protrusion. Starting from a hemorrhoidal enlargement of the third and fourth degree, a surgical intervention in which tissue is removed manually is required for providing relief.
As a rule, hemorrhoidal tissue is formed below the anoderm, i.e. below the transitional skin which is located at the end of the anal canal between the mucous membrane of the rectum and the external skin of the buttock. The anoderm has an extremely high nerve density which ensures sensory continence, i.e. the ability to distinguish gas, liquid or feces and to retain the same.
The methods which have so far been known are concerned with segmental excisions, e.g. according to Milligan-Morgan, in which large incisions are required in the highly sensitive anoderm. This may impair the sensory system of the anoderm and is relatively painful for the patient in the subsequent wound healing process.
U.S. Pat. No. 4,428,748 describes an ophthalmic surgical instrument for treating cataracts of the crystalline lens. The operative attachment of the instrument is needle-shaped and is provided in the area of the tip with a milling opening for removing tissue parts in the area of the crystalline lens. The outer part of the needle can be driven in an ultrasonic surgical manner. For the selective removal of portions of the crystalline lens the needle-like lens is required for selectively treating the parts to be removed within the millimeter range. The instrument is not suited for treating inhomogeneous tissue structures.
EP 0 591 619 A1 discloses a resectioning instrument for the operative removal of tumors, or the like, for instance in the field of gallbladders. An ultrasonic unit is used for reducing the size of the tumor employing an endoscope. The size-reduced tumor particles are removed with the help of a flushing device.
U.S. Pat. No. 4,931,047 suggests an ultrasonic unit for the fragmentation of tumor tissue on the digestive organ. The tissue is fragmented by way of ultrasound to eliminate the tumor.
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U.S. Pat. No. 3,945,375 and U.S. Pat. No. 3,937,222 disclose surgical milling units for the removal of tissue. Each milling unit comprises at least one rotating knife which is rotating in the area of an opening of a sleeve, so that tissue within the area of the opening can be removed by the milling device.
It is the object of the present invention to provide an instrument permitting a simple and gentle surgical removal of hemorrhoidal tissue in accordance with anatomical conditions.
This object is achieved according to the invention by a resectioning instrument for the minimal invasive, subanodermal, submucous removal of hemorrhoidal tissue, with a narrow, elongated carrier device being provided, comprising a vibrating surgical tissue size-reducing device and at least one tissue-removing milling unit.
Only a small incision in the skin is required for the surgical application of said instrument. The incision is preferably made at the base of a hemorrhoidal node on the anal edge region. The anoderm ends in this region or passes into the skin of the buttock. The anoderm is here not incised or only incised to a very slight degree.
Thanks to the small incision, the narrow, elongated carrier device can be introduced below the anoderm. In the subanodermal region the removal of the hemorrhoidal plexus may be started on the front end portion of the instrument.
With the tissue size-reducing device, the hemorrhoidal tissue can be prepared and fragmented in a vibrating surgical manner. It can be isolated from the inner sphincter at the one side and from the anoderm at the other side. The anoderm remains intact and the Musculus internus undamaged.
An ultrasonic surgical tool may e.g. be used as the vibrating surgical device which is e.g. operated within the range of 20,000 to 40,000 Hz. The hemorrhoidal tissue can thus be prepared and fragmented in a very selective manner and without any damage to the healthy tissue.
The prepared tissue can then be reduced in size and removed with the tissue-removing milling unit, so that it is removable piece by piece from the area between the sphincter and the anoderm.
This instrument allows for a very easy operation which does not require any assistance and only needs about a third of the time of conventional surgical methods.
The highly sensitive anoderm remains intact and can subsequently be repositioned into the anal canal in accordance with the anatomy. This means for the patient that less healthy tissue is destroyed, resulting in a faster wound healing process. Because of the maintained anoderm the postoperative wound pain is considerably reduced.
Preferably, when viewed in the longitudinal direction of the carrier device, the tissue size-reducing device can be arranged closer to the tip of the carrier device than the milling unit. As a result, when the instrument is advanced into the hemorrhoidal tissue, the tissue sizereducing device will first get into active contact with the tissue. Preparation and fragmentation will be performed in the advance direction before the milling unit becomes operative.
The tissue size-reducing device can be arranged in a particularly advantageous manner directly at the foremost tip of the carrier device. Thus the preparation can be performed at the foremost end of the carrier device, so that the preparation can be carried out during the selective advance movement of the instrument.
Advantageously, the milling device can be arranged in spaced-apart relationship with the tip of the carrier device in the lateral circumferential area of the carrier device. As a consequence, the milling unit can be operated laterally and, when viewed in the advance direction, will only become active after the hemorrhoidal tissue has been prepared.
Specifically, at least two spaced-apart milling openings of the milling unit may be provided in the lateral circumferential area of the carrier device. Tissue can there by be removed at two sides, so that the hemorrhoidal tissue can be removed relatively rapidly and in different spatial directions.
When viewed in a direction perpendicular to the longitudinal direction, the milling openings should be arranged approximately on the same circumferential line. This ensures that during the advance movement of the instrument the milling action will only begin from a specific circumferential line onwards.
In a preferred embodiment the front end portion may comprise an inclined surface extending at an angle relative to the longitudinal axis of the carrier device, resulting in the formation of a front end portion having an approximately wedge-shaped or beak-shaped cross-section. Such a shape facilitates the advance movement of the instrument in the tissue.
In a particularly advantageous manner, the angle of inclination of the inclined surface may be about 40xc2x0 to 50xc2x0, preferably 45xc2x0, relative to the longitudinal axis of the carrier device. With such an angle, the front end portion is still sufficiently stable and can be advanced relatively easily into the hemorrhoidal tissue.
In a variant of the invention an active surface of the tissue size-reducing device may be integrated at least in part into the inclined surface. As a result, the tissue size-reducing operation can be performed in a direction arranged at a slight angle relative to the advance direction, so that a slightly lateral preparation is also possible.
A light providing device which emits diaphanoscopically usable light is possibly provided on the front end portion. Diaphanoscopy means the transillumination of body parts to detect the structure or contours of tissue by way of shadows. During use of the instrument the surgeon can detect the structure of the hemorrhoidal tissue and its boundaries as well as surrounding tissue and he can selectively push the instrument to the desired place. He will recognize diseased tissue as compared with healthy tissue and detect the position of the front end of the instrument to guide the instrument in a purposeful manner to the desired places. During the process he is looking through the anoderm.
The light providing device may e.g. be an optical-fiber light guide leading to the front end portion and emitting cold light.
Preferably the light providing device may e.g. be arranged in the surface area between the tissue size-reducing device and the milling unit(s). The active surface o f the tissue size-reducing device and the milling unit, respectively, is thereby illuminated and can be seen by the surgeon through the tissue whereby he can control the instrument in a selective manner.
In particular, the light providing device may be disposed in an inclined surface extending at an angle relative to the longitudinal axis of the carrier device. This permits an approximately obliquely bent light emission so that the laterally surrounding area around the front end portion is illuminated in an improved manner and can be seen in a diaphanoscopically improved way.
Possibly, the light providing device is disposed in the circumferential area near the milling unit. As a result, the work portion treated with the milling unit can be illuminated and seen in a particularly clear manner.
The light providing device should have a large-surface light-emitting area relative to the active surfaces of milling unit and/or issue size-reducing device. This ensures a particularly clear illumination of the hemorrhoidal tissue to be treated.
It is particularly advantageous when the carrier device comprises at least one suction channel which is connectable to a vacuum pump and terminates in a suction opening provided on the front end portion. With the help of the suction opening it is possible to produce a slight negative pressure in the front portion so that surrounding tissue is slightly pulled towards the front end portion. This establishes a contact with the vibrating surgical tissue size-reducing device, and the tissue to be removed is supplied to the milling unit.
In a variant of the invention, the suction opening may be centrally provided in an active surface of the tissue size-reducing device. As a result, the surrounding tissue is guided in a relatively selective manner to the active surface, so that the tissue will be reduced in size upon contact.
It is possible to design a milling opening/milling openings as a suction opening in the circumferential area of the carrier device, with a milling knife which is movable in the carrier device being provided in the area thereof. As a result, hemorrhoidal tissue is pulled towards the milling knife because of a small negative pressure.
In a preferred embodiment the carrier device may comprise at least one flushing channel which is connectable to a flushing system and terminates in a flushing opening provided in the front end portion. Flushing liquid can be supplied or discharged via the flushing opening. As a result, the area below the anoderm can be flushed, and possibly free tissue parts can be detached. The flushing liquid may either flow back through a flushing channel of the instrument or exit at the incision site between skin and instrument. The suction channel may also be used for returning flushing liquid. In principle, the same channel may be used as suction channel and flushing channel by successively alternating the direction of flow therethrough.
It is also possible to design a milling opening as a flushing opening in the circumferential area of the carrier device, with the milling knife which is movable in the carrier device being provided in the area thereof. As a result, the flushing liquid can also be used for cleaning the milling unit, for instance in cases where the latter threatens to be clogged by tissue parts. Furthermore, tissue parts can be flushed away through the milling opening. Optionally, the flushing system may also serve to cool the vibrating unit.
Preferably, the flushing opening may be provided centrally in an active surface of the tissue size-reducing device.
Particularly, the carrier device may comprise a first part carrying the front end portion and a second part which is detachably connectable to the first part and designed as a handle.
In a further development of the invention the handle may comprise a marking indicative of the angular orientation of the front end portion relative to the longitudinal axis of the carrier device. With the help of the marking it is possible to detect the rotational position of the front end portion on the externally accessible handle so that the exact position of the tissue size-reducing device and the milling unit, respectively, can be made out.
The milling unit is possibly provided with a milling knife which is movable in the carrier device and arranged in the area of a milling opening of the carrier device. The milling knife can e.g. rotate in the carrier device, with the knife being provided in the area of the milling opening. Tissue which is positioned inside the area of the milling opening is cut by the milling knife in metered amounts and removed. Thanks to the arrangement of the milling knife within the carrier device, the milling knife can be introduced into the tissue in a relatively protected manner and moved therein. Tissue is only removed in the area of the milling opening. A milling unit of such a configuration may also be designated as a xe2x80x9cshaverxe2x80x9d.
According to a preferred embodiment the tissue size-reducing device and/or the milling unit can be supported in the carrier device in a longitudinally displaceable manner. The tissue size-reducing device can thereby be advanced in a selective manner to the tumor parts to be treated. The carrier device may e.g. be designed as a sleeve or trocar in which the tissue size-reducing device can be manually introduced from behind and slid beyond the front end of the trocar.
Preferably, the active surface of the tissue size-reducing device can be pushed out of the carrier device into a position in which the active surface projects forwards from the carrier device. Thus the active surface can serve as the foremost tip which advances in the tissue portion by portion and provides room for the trailing carrier device. As a result, the active surface is not automatically fixed to the shape of the front end portion of the carrier device, but can project separately, e.g. in the form of a finger, from the carrier device.
Particularly, the active surface of the tissue reducing device may have an approximately oval or circular shape.